The section inside the ring is a particularly weak point in an otherwise nearly-impenetrable shield.
“Do it!” Krennic roared, and Ramda and his men scurried to act. When
the orders had been given, Krennic lowered his voice but still heard
himself quivering with fury. “Is there any way,” he asked, “that the
rebel fleet can break through the shield? Think ...
The Profundity is confirmed in its Star Wars Databank article to have been part of the Exodus Fleet that left the Mon Calamari homeworld when the Empire subjugated the surface. As such, it appears that the ship can be docked (in an upright fashion) anywhere there's a large enough expanse of water.
The Profundity began its life as a daring ...
Director Gareth Edwards has stated in interviews that he doesn't think it likely that an 'alternate cut' will ever see the light of day, or even many deleted scenes. The film was so VFX heavy that unfinished scenes are basically unwatchable nonsense and quite a lot of it wouldn't make much sense anyway since it's so divorced from the earlier plot.
When the Death Star fires on Jedha City, it misses completely, by a few kilometers
You seem to be mistaken, the movie has proved the Death Star to be a deadly accurate weapon.
The Holy City of Jedha was destroyed with frightening precision in one shot. It was the hidden base of Saw Gerrera that was destroyed a few kilometers away.
Why was the Death Star ...
The first line of the Rogue One novelisation pretty much gives the game away.
Galen Erso was not a good farmer.
Someone with Erso's obvious talents, intellect and the financial backing to buy a farm (but near-total incompetence as a farmer and zero interest in buying outland tools and materials), turning up with his family in tow onto a small agrarian ...
That area was designed to be opened and closed regularly. The rest of the shield around the planet stayed active at all times. That one area is presumably a weaker area so they had a better chance to break through.
It's a game of strategy
Even if we consider that dice or some element of randomness plays into the game (like many real-world games which would easily be considered strategy, such as RISK), we can presume, merely from it's introductory scene, that ultimately, it's a game of tactics. Let's look at the script:
All of the squadron members receive a name (and a small bio) in the Rogue One Visual Dictionary
They took off very quickly and presumably jumped to lightspeed inadvisably close to the planet's gravity well, taking them outside the Rebel's sphere of influence in a very short period of time.
“There is no ‘Rogue One,’” the person on the comm responded.
“There is now,” K-2 said.
Bodhi gunned the engines and took the shuttle into the air.
“Rogue One ...
I have to make the comment by @amflare a proper answer, because I think it is the most likely:
With the wings folded up into landing position the shuttle has a much smaller footprint, i.e. uses less space.
The shield gate is, by design, a bottle neck for all traffic - it thus stands to reason that you would make sure that passing ships use the smallest ...